A Study to Compare Upadacitinib (ABT-494) to Placebo in Adults With Rheumatoid Arthritis (RA) Who Are on a Stable Dose of Conventional Synthetic Disease-Modifying Anti-Rheumatic Drugs (csDMARDs) and Have an Inadequate Response to csDMARDs

This study consisted of a 35-day screening period; a 12-week randomized, double-blind, parallel-group, placebo-controlled treatment period (Period 1); a 248-week blinded long-term extension period (Period 2); and a 30-day follow-up period (call or visit). Participants who met eligibility criteria were randomized in a 3:3:3:1:1:1 ratio to one of six treatment groups: * Group 1: Upadacitinib 7.5 mg QD (Period 1) → upadacitinib 7.5 mg QD (Period 2) * Group 2: Upadacitinib 15 mg QD (Period 1) → upadacitinib 15 mg QD (Period 2) * Group 3: Upadacitinib 30 mg QD (Period 1) → upadacitinib 30 mg QD (Period 2) * Group 4: Placebo (Period 1) → upadacitinib 7.5 mg QD (Period 2) * Group 5: Placebo (Period 1) → upadacitinib 15 mg QD (Period 2) * Group 6: Placebo (Period 1) → upadacitinib 30 mg QD (Period 2)